CHIPS Prototype Deployment
In order to prove the viability of the CHIPS experiment concept and that the challenges of operating giant enclosed detectors deep underwater can be overcome, so far a small prototype detector called CHIPS-M was deployed in the Summer of 2014, and then lifted out early Summer 2015, modified and then redeployed in the same location later that Summer. This prototype was much smaller than the real CHIPS detector will be but it serves to test the various technologies involved. For example, the way the outer liner is sealed to make the inner volume light tight is very important. Any stray light (for example even from the moon in the night) will affect the event rate and reconstruction of real neutrino events. The electronics need to be water tight to work and the water needs to be continuously filtered to maintain purity. All these things need to work flawlessly at a depth of tens of meters in the lake, at a water pressure of several atmospheres. The pictures below show the CHIPS-M detector as it was being lifted out of the Wentworth pit and afterwards. The bottom picture shows a prototype of a new PMT array for the second deployment of CHIPS-M.